"Over the past few years, we've seen tremendous improvements in the treatment of people with CLL and SLL. Newly introduced medications can improve the outcome of therapy, particularly for patients with high-risk prognostic markers who typically do not respond well to standard chemotherapy," said Thomas J. Kipps, M.D., Ph.D., University of California San Diego, Moores Cancer Center and lead investigator of the study.† "Analysis of the clinical data suggests an improvement in outcomes for certain high-risk CLL/SLL patients treated with IMBRUVICA."
CLL is a type of cancer that starts from cells that become certain white blood cells (called lymphocytes) in the bone marrow. The cancer (leukemia) cells start in the bone marrow but then go into the blood. There are approximately 19,000 newly diagnosed CLL patients every year.1 SLL is a slow-growing lymphoma biologically similar to CLL in which too many immature white blood cells cause lymph nodes to become larger than normal.2 CLL/SLL are predominately a disease of the elderly, with a median age of 71 at diagnosis.3 Genomic abnormalities in CLL, including del 11q, deletion 17p (del 17p), trisomy 12, CK and IGHV, are detected in up to 80 percent of patients and play an important role in disease pathogenesis and evolution, determining patient outcomes and therapeutic strategies.6
"We are encouraged by the findings from these analyses, which add to the large body of data supporting IMBRUVICA in treating CLL/SLL patients," said Danelle James, M.D., M.S., Head of Clinical Science, Pharmacyclics LLC, an AbbVie company. "We have one of the most robust databases for a single molecule in hematological oncology and more than 25,000 CLL patients have been treated in the U.S. alone with IMBRUVICA since approval in 2014. We continue to investigate the use of IMBRUVICA in high-risk patients so that ideally they too can achieve better response rates and overall outcomes to treatment."
Abstract #19: Outcomes of Ibrutinib-Treated Patients with Chronic Lymphocytic Leukemia/Small Lymphocytic Leukemia (CLL/SLL) with High-Risk Prognostic Factors in an Integrated Analysis of 3 Randomized Phase 3 Studies
Data from three studies, RESONATE, RESONATE-2 and HELIOS, were pooled to analyze the outcomes of IMBRUVICA and comparator-treated patients when separated on the basis of genomic abnormality. The ORR in patients treated with IMBRUVICA was 89 percent in unmutated IGHV, 88 percent in del 11q, 86 percent in trisomy 12 and 87 percent in CK, with patients achieving a CR rate of 22 percent in unmutated IGHV, 18 percent in del 11q, 25 percent in trisomy 12 and 10 percent in CK. At 24 months, in patients treated with IMBRUVICA, PFS was 78 percent in unmutated IGHV, 82 percent in del 11q, 77 percent in trisomy 12 and 76 percent in CK. In patients treated with IMBRUVICA, at 30 months, OS was 88 percent in unmutated IGHV, 93 percent in del 11q, 89 percent in trisomy 12 and 84 percent in CK.3
In each subgroup, PFS, OS, ORR and CR rates trended higher in IMBRUVICA-treated patients versus comparator-treated patients, regardless of genomic factors. In IMBRUVICA-treated patients, unmutated IGHV, del 11q, trisomy 12 or CK were generally not associated with shorter PFS or OS, or decreased ORR or CR rate. Further, in IMBRUVICA-treated patients, del 11q was associated with a trend of longer PFS (82 percent at 24 months for those with del 11q, compared with 75 percent for those without del 11q) and OS (93 percent at 30 months for those with del 11q, compared with 86 percent for those without del 11q) and trisomy 12 with increased CR rate (25 percent for those with trisomy 12, compared with 6 percent for those without trisomy 12). In a multivariate analysis, ibrutinib-treated patient outcomes in those only having received one or more prior lines of therapy versus treatment in the first-line was associated with shorter PFS and OS.3
In RESONATE, patients received IMBRUVICA 420 mg once daily until disease progression or ofatumumab for up to 24 weeks. In RESONATE-2, patients age 65 or older with treatment-naïve CLL/SLL, not including del 17p, received IMBRUVICA 420 mg once daily until disease progression, or chlorambucil. In HELIOS, a Janssen-sponsored, randomized, multi-center, double-blind study, previously treated CLL/SLL patients were randomized to receive IMBRUVICA or placebo, once daily continuing until disease progression or unacceptable toxicity with six cycles of BR.3
Adverse events (AEs) were similar in patients with or without genomic factors, and reflect a median treatment exposure of 19-20 months for IMBRUVICA-treated patients and 5-10 months for comparator-treated patients. Discontinuation due to AEs ranged from 8-15 percent in IMBRUVICA-treated patients and 13-17 percent in comparator-treated patients.3
P-values ranged from 0.03-0.96. To view more abstract data, including all P-values, see Table 1 and Table 2 at the end.
About IMBRUVICA
IMBRUVICA (ibrutinib) is a first-in-class, oral, once-daily therapy that inhibits a protein called Bruton's tyrosine kinase (BTK). BTK is a key signaling molecule in the B-cell receptor signaling complex that plays an important role in the survival and spread of malignant B cells.4,5 IMBRUVICA blocks signals that tell malignant B cells to multiply and spread uncontrollably.4
IMBRUVICA is FDA-approved in five distinct patient populations: CLL, SLL, WM, along with previously-treated MCL and MZL.4
Accelerated approval was granted for the MCL and MZL indications based on overall response rate. Continued approval for MCL and MZL may be contingent upon verification and description of clinical benefit in confirmatory trials.4
IMBRUVICA was one of the first medicines to receive U.S. FDA approval via the new Breakthrough Therapy Designation pathway.
IMBRUVICA is being studied alone and in combination with other treatments in several blood and solid tumor cancers and other serious illnesses. IMBRUVICA has one of the most robust clinical oncology development programs for a single molecule in the industry, with approximately 130 ongoing clinical trials. There are total of 30 ongoing company-sponsored trials, 14 of which are in Phase 3, and approximately 100 investigator-sponsored trials and external collaborations that are active around the world. To date, more than 65,000 patients around the world have been treated with IMBRUVICA in clinical practice and clinical trials.
Hemorrhage - Fatal bleeding events have occurred in patients treated with IMBRUVICA®. Grade 3 or higher bleeding events (intracranial hemorrhage [including subdural hematoma], gastrointestinal bleeding, hematuria, and post-procedural hemorrhage) have occurred in up to 6% of patients. Bleeding events of any grade, including bruising and petechiae, occurred in approximately half of patients treated with IMBRUVICA®.
The mechanism for the bleeding events is not well understood. IMBRUVICA® may increase the risk of hemorrhage in patients receiving antiplatelet or anticoagulant therapies and patients should be monitored for signs of bleeding. Consider the benefit-risk of withholding IMBRUVICA® for at least 3 to 7 days pre- and postsurgery depending upon the type of surgery and the risk of bleeding.
Infections - Fatal and nonfatal infections have occurred with IMBRUVICA® therapy. Grade 3 or greater infections occurred in 14% to 29% of patients. Cases of progressive multifocal leukoencephalopathy (PML) and Pneumocystis jirovecii pneumonia (PJP) have occurred in patients treated with IMBRUVICA®. Evaluate patients for fever and infections and treat appropriately.
Cytopenias - Treatment-emergent Grade 3 or 4 cytopenias including neutropenia (range, 13% to 29%), thrombocytopenia (range, 5% to 17%), and anemia (range, 0% to 13%) based on laboratory measurements occurred in patients treated with single agent IMBRUVICA®. Monitor complete blood counts monthly.
Atrial Fibrillation - Atrial fibrillation and atrial flutter (range, 6% to 9%) have occurred in patients treated with IMBRUVICA®, particularly in patients with cardiac risk factors, hypertension, acute infections, and a previous history of atrial fibrillation. Periodically monitor patients clinically for atrial fibrillation. Patients who develop arrhythmic symptoms (eg, palpitations, lightheadedness) or new-onset dyspnea should have an ECG performed. Atrial fibrillation should be managed appropriately and if it persists, consider the risks and benefits of IMBRUVICA® treatment and follow dose modification guidelines.
Hypertension - Hypertension (range, 6% to 17%) has occurred in patients treated with IMBRUVICA® with a median time to onset of 4.6 months (range, 0.03 to 22 months). Monitor patients for new-onset hypertension or hypertension that is not adequately controlled after starting IMBRUVICA®. Adjust existing antihypertensive medications and/or initiate antihypertensive treatment as appropriate.
Second Primary Malignancies - Other malignancies (range, 3% to 16%) including non-skin carcinomas (range, 1% to 4%) have occurred in patients treated with IMBRUVICA®. The most frequent second primary malignancy was non-melanoma skin cancer (range, 2% to 13%).
Tumor Lysis Syndrome - Tumor lysis syndrome has been infrequently reported with IMBRUVICA® therapy. Assess the baseline risk (eg, high tumor burden) and take appropriate precautions. Monitor patients closely and treat as appropriate.
Embryo-Fetal Toxicity - Based on findings in animals, IMBRUVICA® can cause fetal harm when administered to a pregnant woman. Advise women to avoid becoming pregnant while taking IMBRUVICA® and for 1 month after cessation of therapy. If this drug is used during pregnancy or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus. Advise men to avoid fathering a child during the same time period.
The most common adverse reactions (≥20%) in patients with B-cell malignancies (MCL, CLL/SLL, WM and MZL) were neutropenia** (61%), thrombocytopenia** (62%), diarrhea (43%), anemia** (41%), musculoskeletal pain (30%), rash (30%), nausea (29%), bruising (30%), fatigue (29%), hemorrhage (22%), and pyrexia (21%).
** Based on adverse reactions and/or laboratory measurements (noted as platelets, neutrophils, or hemoglobin decreased).
The most common Grade 3 or 4 non-hematologic adverse reactions (≥5%) in MCL patients were pneumonia (7%), abdominal pain (5%), atrial fibrillation (5%), diarrhea (5%), fatigue (5%), and skin infections (5%).
The most common Grade 3 or 4 non-hematologic adverse reactions (≥5%) in MZL patients were pneumonia (10%), fatigue (6%), diarrhea (5%), rash (5%), and hypertension (5%).
Approximately 6% (CLL/SLL), 14% (MCL), 11% (WM) and 10% (MZL) of patients had a dose reduction due to adverse reactions. Approximately 4%-10% (CLL/SLL), 9% (MCL), and 9% (WM [6%] and MZL [13%]) of patients discontinued due to adverse reactions. Most common adverse reactions leading to discontinuation were pneumonia, hemorrhage, atrial fibrillation, rash, and neutropenia (1% each) in CLL/SLL patients and subdural hematoma (1.8%) in MCL patients. The most common adverse reactions leading to discontinuation were interstitial lung disease, diarrhea, and rash (1.6% each) in WM and MZL patients.
CYP3A Inhibitors - Avoid coadministration with strong and moderate CYP3A inhibitors. If a moderate CYP3A inhibitor must be used, reduce the IMBRUVICA® dose.
Hepatic Impairment - Avoid use in patients with moderate or severe baseline hepatic impairment. In patients with mild impairment, reduce IMBRUVICA® dose.
About AbbVie
AbbVie is a global, research-driven biopharmaceutical company committed to developing innovative advanced therapies for some of the world's most complex and critical conditions. The company's mission is to use its expertise, dedicated people and unique approach to innovation to markedly improve treatments across four primary therapeutic areas: immunology, oncology, virology and neuroscience. In more than 75 countries, AbbVie employees are working every day to advance health solutions for people around the world. For more information about AbbVie, please visit us at www.abbvie.com. Follow @abbvie on Twitter, Facebook or LinkedIn.
Forward-Looking Statements
Some statements in this news release may be forward-looking statements for purposes of the Private Securities Litigation Reform Act of 1995. The words "believe," "expect," "anticipate," "project" and similar expressions, among others, generally identify forward-looking statements. AbbVie cautions that these forward-looking statements are subject to risks and uncertainties that may cause actual results to differ materially from those indicated in the forward-looking statements. Such risks and uncertainties include, but are not limited to, challenges to intellectual property, competition from other products, difficulties inherent in the research and development process, adverse litigation or government action, and changes to laws and regulations applicable to our industry. Additional information about the economic, competitive, governmental, technological and other factors that may affect AbbVie's operations is set forth in Item 1A, "Risk Factors," in AbbVie's 2015 Annual Report on Form 10-K, which has been filed with the Securities and Exchange Commission. AbbVie undertakes no obligation to release publicly any revisions to forward-looking statements as a result of subsequent events or developments, except as required by law.
†Disclaimer: Dr. Kipps served as investigator of Pharmacyclics-sponsored clinical studies as noted.Dr. Kipps does not have a financial interest in the company.
Table 2. Efficacy Outcomes in Ibrutinib- and Comparator-Treated Patients by Genomic Prognostic Factors (Univariate)
To view the original version on PR Newswire, visit:http://www.prnewswire.com/news-releases/imbruvica-ibrutinib-pooled-outcomes-data-from-three-phase-3-studies-suggest-potential-clinical-efficacy-in-patients-with-high-risk-chronic-lymphocytic-leukemiasmall-lymphocytic-lymphoma-cllsll-300457242.html

Among 12- to 17-year-olds who have never used tobacco products, nearly half were considered receptive to tobacco marketing if they were able to recall or liked at least one advertisement, report a coalition of behavioral scientists in a new national study. Receptivity to tobacco ads is associated with an increased susceptibility to smoking cigarettes in the future.
Led by researchers at University of California San Diego Moores Cancer Center and Dartmouth's Norris Cotton Cancer Center, the researchers analyzed data from the Population Assessment of Tobacco and Health (PATH) Study, which included interviews with 10,751 adolescents who reported having never used any type of tobacco product. Risk to use a tobacco product in the future was the researchers' main point of interest. The findings are published in the May 22 issue of Pediatrics.
"Tobacco marketing restrictions differ by product with only e-cigarettes allowed to be advertised on television," said John P. Pierce, PhD, Professor Emeritus in the Department of Family Medicine and Public Health at UC San Diego School of Medicine and Moores Cancer Center and lead author on the study. "Previous studies have linked receptivity to cigarette advertising with susceptibility to smoke cigarettes among youth. What we're seeing in this study is that even being receptive to marketing of non-cigarette tobacco products, including e-cigarettes, is associated with susceptibility to smoke cigarettes."
In this analysis of the first wave of data from the PATH Study, respondents were considered susceptible to tobacco or committed to never using these products based on responses to three questions assessing their curiosity about the product, intention to try it in the near future, and likely response if a best friend were to offer them the product. Only those with the strongest rejection to all three questions were categorized as committed to never use. All others were susceptible. This index has been validated in multiple studies.
Participants were shown 20 tobacco ads chosen randomly from 959 ads representing all available recent commercials used in print, direct mail, internet or television advertisements. Each respondent was asked initially to name his or her favorite tobacco ad and then shown a random set of five ads for each of the following products: cigarettes, e-cigarettes, cigars and smokeless products. For each ad presented, they were asked if they had seen the ad in the past 12 months and whether they liked the ad. Aided recall was classified as low receptivity while image-liking or favorite ad was considered to be higher.
A high proportion of under-aged adolescents in the United States are still exposed to tobacco advertising. The study found that 41 percent of 12- to 13-year-olds, and about half of both 14- to 15-year-olds and 16- to 17-year-olds were receptive to any type of tobacco advertising.
"Six of the top 10 most recognized tobacco ads by adolescents were for e-cigarettes, four of which were aired on TV," said James Sargent, MD, director of the C. Everett Koop Institute at Dartmouth and co-author. "The PATH Study will continue to track these adolescents who have not used tobacco and will be able to identify if receptivity to marketing for different tobacco products during wave 1 of the study -- particularly e-cigarette marketing -- increases cigarette smoking one or two years later."
Receptivity to advertising was highest for e-cigarettes with 28 to 33 percent across age groups, followed by 22 to 25 percent for cigarettes and 15 to 21 percent for cigars. E-cigarette advertising is of interest to researchers because of its presence on television and because showing people vaping is very similar to showing people smoking, said Pierce.
The proportion who were susceptible to using tobacco products increased with the level of receptivity. Fifty percent of respondents considered to have low receptivity, 65 percent who were moderately receptive and 87 percent of youth who were deemed highly receptive were susceptible to use tobacco products.
"Cigarette smoking is still a major problem and a major cause of lung cancer and other diseases," said Pierce. "We've had big declines in the number of people who initiated smoking, but it is important that we maintain that reduction."
Co-authors include: Martha White, David R. Strong, Eric Leas, Madison Noble, Dennis Trinidad, Karen Messer, UC San Diego; Nicolette Borek, David B. Portnoy, Blair N. Coleman, US Food and Drug Administration; Victoria R. Green, National Institutes of Health and Kelly Government Solutions; Annette R. Kaufman, National Cancer Institute; Cassandra A. Stanton, Westat and Georgetown University Medical Center; Maansi Bansal-Travers, Andrew Hyland, Roswell Park Cancer Institute; Jennifer Pearson, Johns Hopkins University and Schroeder Institute for Tobacco Research and Policy Studies at Truth Initiative; Meghan B. Moran, Johns Hopkins University; and Charles Carusi, Westat.

Previous studies identified the Hippo pathway kinases LATS1/2 as a tumor suppressor, but new research led by University of California San Diego School of Medicine scientists reveals a surprising role for these enzymes in subduing cancer immunity. The findings, published in Cell on December 1, could have a clinical role in improving efficiency of immunotherapy drugs.
"Before our study, no one knew that the Hippo pathway was regulating immunogenicity," said first author Toshiro Moroishi, MD, PhD, postdoctoral researcher at UC San Diego Moores Cancer Center. "LATS1/2 deletion in cancer cells improves tumor immunogenicity, leading to the destruction of cancerous cells by enhancing anti-tumor immune responses."
Hippo pathway signaling regulates organ size by moderating cell growth, apoptosis and stem cell renewal, but dysregulation contributes to cancer development. In vitro studies of Hippo pathway kinases LATS1/2 showed that the loss of these enzymes promoted cell proliferation and tumor survival. In vivo research using immune-compromised mouse models also supports a tumor suppressor function of the Hippo pathway.
However, when Moroishi and team deleted LATS1/2 from mouse cancer cells and examined tumor growth in models with healthy immune systems researchers found that immunogenicity -- the ability to stimulate an immune response -- improved, destroying cancer cells. Researchers caution that immune systems of mouse models are different from the human immune system so the response might be different and further studies are needed.
If the outcome proves to be the same, using a LATS1/2 inhibitor alone or in combination with an immune checkpoint inhibitor may stimulate the immune system of patients that previously did not respond to immunotherapy treatments.
Currently, most immunotherapy research focuses on targeting the immune system, but the new findings reveal that tumor cells may also be vulnerable to inhibitors.
"Inhibiting LATS1/2 could be an attractive approach to treat cancer," said Kun-Liang Guan, PhD, Distinguished Professor of Pharmacology at Moores Cancer Center and senior author of the study. "LATS is an ideal target because there are many kinase inhibitors that have been successfully developed as cancer drugs."
This study focused on breast cancer, melanoma and squamous cell carcinoma but the same could be applied to other cancers, said Moroishi.
Study co-authors include: Tomoko Hayashi, Yu Fujita, Dennis A. Carson, UC San Diego; Wei-Wei Pan, UC San Diego and Jiaxing University; Matthew V. Holt, and Jun Qin, Baylor College of Medicine.
Disclosure: Kun-Liang Guan is co-founder of Vivace Therapeutics and holds equity interest.

Acute myeloid leukemia (AML) is an aggressive cancer known for drug resistance and relapse. In an effort to uncover new treatment strategies, researchers at University of California San Diego School of Medicine and Moores Cancer Center discovered that a cell surface molecule known as CD98 promotes AML. The study, published October 27 by Cancer Cell, also shows that inhibiting CD98 with the therapeutic antibody IGN523 blocks AML growth in patient-derived cells and mouse models.
"To improve therapeutic strategies for this disease, we need to look not just at the cancer cells themselves, but also at their interactions with surrounding cells, tissues, molecules and blood vessels in the body," said co-senior author Tannishtha Reya, PhD, professor of pharmacology at UC San Diego School of Medicine and Moores Cancer Center. "In this study, we identified CD98 as a critical molecule driving AML growth. We showed that blocking CD98 can effectively reduce leukemia burden and improve survival by preventing cancer cells from receiving support from the surrounding environment."
Reya led the study together with Mark Ginsberg, MD, professor of medicine at UC San Diego School of Medicine and Moores Cancer Center. Co-author Edward van der Horst, PhD, senior director at Igenica Biotherapeutics Inc., provided the anti-CD98 antibody IGN523.
AML is a type of cancer in which the bone marrow makes abnormal white blood cells, red blood cells or platelets. Reya's team and others have previously shown that leukemia cells interact with their surroundings in the body via molecules on their cell surfaces, and that these interactions can help the cancer cells divide, replicate and metastasize.
CD98 is a molecule found on the surface of cells, where it controls how cells stick to one another. CD98 is known to play a role in the proliferation and activation of certain immune cells. CD98 levels are also known to be elevated in some solid tumors, and linked to poor prognosis.
To determine CD98's role in AML, in this latest study Reya's team engineered mouse models that lack the molecule. They found that the loss of CD98 blocked AML growth and improved survival. CD98 loss largely spared normal blood cells, which the researchers said indicates a potential therapeutic window. Further experiments revealed that leukemia cells lacking CD98 had fewer stable interactions with the lining of blood vessels -- interactions that were needed to fuel AML growth.
Next, the researchers wanted to see what would happen if they blocked CD98 in AML with a deliverable inhibitor. In 2015, Igenica Biotherapeutics Inc. tested IGN523, a humanized antibody that specifically binds and inhibits CD98, in a phase 1 clinical trial at Moores Cancer Center and elsewhere. The trial's goal was to determine a safe dose for IGN523 administration in AML patients. In this study, Reya and team tested IGN523 in their own AML models.
The researchers found that IGN523 blocks CD98's AML-promoting activity in both mouse models of AML and human cells in the laboratory. They also transplanted human patient-derived AML cells into mice and treated the recipients soon after with either IGN523, the anti-CD98 antibody, or with a control antibody. Anti-CD98-treatment effectively eliminated AML cells. In contrast, AML in control mice expanded more than 100-fold.
"This study suggests that human AML can't get established without CD98, and that blocking the molecule with anti-CD98 antibodies could be beneficial for the treatment of AML in both adults and children," Reya said.
Moving forward, Reya and team are working to further define whether CD98 could be targeted to treat pediatric AML.
"Many of the models we used in this work were based on mutations found in childhood AML," she said. "While many childhood cancers have become very treatable, childhood AML continues to have a high rate of relapse and death. We plan to work with pediatric oncologists to test if anti-CD98 agents can be effective against pediatric AML, and whether it can improve responses to current treatments. I think this is particularly important to pursue since the anti-CD98 antibody has already been through phase I trials, and could be more easily positioned to test in drug-resistant pediatric AML."
The American Cancer Society estimates that there will be about 19,950 new cases of AML and about 10,430 deaths from the disease in the United States in 2016, mostly adults. Approximately 500 children are diagnosed with AML in the U.S. each year, and it's the most common second cancer among children treated for other cancers, according to St. Jude Children's Research Hospital.

Acute myeloid leukemia (AML) is an aggressive cancer known for drug resistance and relapse. In an effort to uncover new treatment strategies, researchers at University of California San Diego School of Medicine and Moores Cancer Center discovered that a cell surface molecule known as CD98 promotes AML. The study, published October 27 by Cancer Cell, also shows that inhibiting CD98 with the therapeutic antibody IGN523 blocks AML growth in patient-derived cells and mouse models.
"To improve therapeutic strategies for this disease, we need to look not just at the cancer cells themselves, but also at their interactions with surrounding cells, tissues, molecules and blood vessels in the body," said co-senior author Tannishtha Reya, PhD, professor of pharmacology at UC San Diego School of Medicine and Moores Cancer Center. "In this study, we identified CD98 as a critical molecule driving AML growth. We showed that blocking CD98 can effectively reduce leukemia burden and improve survival by preventing cancer cells from receiving support from the surrounding environment."
Reya led the study together with Mark Ginsberg, MD, professor of medicine at UC San Diego School of Medicine and Moores Cancer Center. Co-author Edward van der Horst, PhD, senior director at Igenica Biotherapeutics Inc., provided the anti-CD98 antibody IGN523.
AML is a type of cancer in which the bone marrow makes abnormal white blood cells, red blood cells or platelets. Reya's team and others have previously shown that leukemia cells interact with their surroundings in the body via molecules on their cell surfaces, and that these interactions can help the cancer cells divide, replicate and metastasize.
CD98 is a molecule found on the surface of cells, where it controls how cells stick to one another. CD98 is known to play a role in the proliferation and activation of certain immune cells. CD98 levels are also known to be elevated in some solid tumors, and linked to poor prognosis.
To determine CD98's role in AML, in this latest study Reya's team engineered mouse models that lack the molecule. They found that the loss of CD98 blocked AML growth and improved survival. CD98 loss largely spared normal blood cells, which the researchers said indicates a potential therapeutic window. Further experiments revealed that leukemia cells lacking CD98 had fewer stable interactions with the lining of blood vessels -- interactions that were needed to fuel AML growth.
Next, the researchers wanted to see what would happen if they blocked CD98 in AML with a deliverable inhibitor. In 2015, Igenica Biotherapeutics Inc. tested IGN523, a humanized antibody that specifically binds and inhibits CD98, in a phase 1 clinical trial at Moores Cancer Center and elsewhere. The trial's goal was to determine a safe dose for IGN523 administration in AML patients. In this study, Reya and team tested IGN523 in their own AML models.
The researchers found that IGN523 blocks CD98's AML-promoting activity in both mouse models of AML and human cells in the laboratory. They also transplanted human patient-derived AML cells into mice and treated the recipients soon after with either IGN523, the anti-CD98 antibody, or with a control antibody. Anti-CD98-treatment effectively eliminated AML cells. In contrast, AML in control mice expanded more than 100-fold.
"This study suggests that human AML can't get established without CD98, and that blocking the molecule with anti-CD98 antibodies could be beneficial for the treatment of AML in both adults and children," Reya said.
Moving forward, Reya and team are working to further define whether CD98 could be targeted to treat pediatric AML.
"Many of the models we used in this work were based on mutations found in childhood AML," she said. "While many childhood cancers have become very treatable, childhood AML continues to have a high rate of relapse and death. We plan to work with pediatric oncologists to test if anti-CD98 agents can be effective against pediatric AML, and whether it can improve responses to current treatments. I think this is particularly important to pursue since the anti-CD98 antibody has already been through phase I trials, and could be more easily positioned to test in drug-resistant pediatric AML."
The American Cancer Society estimates that there will be about 19,950 new cases of AML and about 10,430 deaths from the disease in the United States in 2016, mostly adults. Approximately 500 children are diagnosed with AML in the U.S. each year, and it's the most common second cancer among children treated for other cancers, according to St. Jude Children's Research Hospital.

PubMed | University of California at San Diego and Moores Cancer Center andType: Journal Article | Journal: Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

Pathological antibodies have been demonstrated to play a key role in type II immune hypersensitivity reactions, resulting in the destruction of healthy tissues and leading to considerable morbidity for the patient. Unfortunately, current treatments present significant iatrogenic risk while still falling short for many patients in achieving clinical remission. In the present work, we explored the capability of target cell membrane-coated nanoparticles to abrogate the effect of pathological antibodies in an effort to minimize disease burden, without the need for drug-based immune suppression. Inspired by antibody-driven pathology, we used intact RBC membranes stabilized by biodegradable polymeric nanoparticle cores to serve as an alternative target for pathological antibodies in an antibody-induced anemia disease model. Through both in vitro and in vivo studies, we demonstrated efficacy of RBC membrane-cloaked nanoparticles to bind and neutralize anti-RBC polyclonal IgG effectively, and thus preserve circulating RBCs.